• Journal of Life Science
• /
• v.16 no.1
• /
• pp.22-29
• /
• 2006

Effect of microbial products made of Bacillus stearothermophilus DL-3 on growth of chickens and pigs was investigated. Two types of microbial product were made in this study. One is the microbial product made of culture broth of B. stearothemophilus DL-3 and rice bran which named as the microbial product A. The other is the microbial product made of culture broth of B. stearothermophilus DL-3, apple pomace, soybean pomace and rice bran which named as the microbial product B. Chickens were divided into three groups and each group was fed with $100\%$ general feed, $90\%$ general feed supplemented with $10\%$ microbial product A or $90\%$ general feed supplemented with $10\%$ microbial product B. The average chicken weight of each group was $41.1{\pm}2.5g,\;41.6{\pm}3.2g\;and\;42.3{\pm}2.9g$ and those after 28 days was $547.7{\pm}91.7g,\;560.1{\pm}17.2g\;and\;562.2{\pm}32.5g$, respectively. The average weight gain for each group was 506.6 g, 518.6 g and 519.9 g, respectively, and weight increases of groups fed with $90\%$ general feeder and $10\%$ microbial product A and B were $2.4\%\;and\;2.6\%$ higher than the group fed with $100\%$ general feed. Pigs were also divided into three groups and each group was fed like chickens. The average weight of each group was $9.3{\pm}1.0kg,\;9.4{\pm}1.1kg\;and\;9.6{\pm}1.0kg$ and those after 37 days was $19.3{\pm}4.1kg,\;20.2{\pm}3.9kg\;and\;20.8{\pm}4.2kg$, respectively. The average Weight gain for each group was 10.65 kg, 10.82 kg and 11.20 kg, respectively, and weight increases of groups fed with $90\%$ general feeder and $10\%$ microbial product A and B were $1.6\%$ and $5.2\%$ higher than the group fed with $100\%$ general feed.

• Microbiology and Biotechnology Letters
• /
• v.19 no.6
• /
• pp.592-597
• /
• 1991

An extracellular xylanase of Bacillus stearothemophilus was purified to a single protein through a sequency of operations including ammonium sulfate fractionation, DEAE Sepharose CL-6B ion exchange chromatography, Sephadex G-100 gel filtration and heat treatment. The purified enzyme had a moleular weight of 170, 000. the pH and temperature optima for the enzyme activity were pH 9.0 and $55^{\circ}C$, respectively. The activity was enhanced by $co^{2+} \; and\; Mn^{2+}$, and inhibited by $Hg^{2+}$. Pattern of hydrolysis demonstrated that the xylanase was an endo-splitting enzyme able to break down larchwood xylan at random giving xylobiose and xylotriose as the main end products.

• 한국생물공학회:학술대회논문집
• /
• 2000.11a
• /
• pp.167-170
• /
• 2000

Proteolytic hydrolysis is one of the main enzymatic reaction of waste activated sludge (WAS) digestion. Pretense excreted from Bacillus stearothermophilus (ATCC 31197) showed optimum temperature of $75^{\circ}C$ for maxium heat stable proteolytic activity against azo casein. The dependency of $Ca^{2+}$, $Zn^{2+}$ on heat stability of proteolytic enzymes were measured with various concentrations. It was shown that $Ca^{2+}$ ion enhanced heat stability of these enzymes. Then thermophilic aerobic digestion (TAD) was performed using B. sterothermophilus with the addition of divalent ions. Performance of TAD process with ATCC 31197 activated by $Ca^{2+}$, $Zn^{2+}$ions in terms of dissolved organic carbon (DOC) concentration, extracellular protein concentration, and scanning electrion microscopy (SEM) analysis. The best result of protein reduction concentration in digestion test was obtained with the addition of 2 mM $Ca^{2+}$ ion.

• Microbiology and Biotechnology Letters
• /
• v.31 no.2
• /
• pp.111-116
• /
• 2003

The xylA gene of Bacillus stearothermophilus No. 236 encoding $\beta$-xylosidase was cloned and sequenced previously. The transcriptional start site of the xylA gene cloned in E. coli was identified to be the guanine (G) by primer extension analysis. This supports that the expression of xylA gene is also directed in the E. coli cells by the previously determined transcription initiation signals, -10 sequence (CATAAT) and -35 sequence (TTGTTA) separated by 12 bp. To increase the expression of $\beta$-xylosidase, firstly the spacer region of xylA promoter was extended from 12 to 17 bp, and then the -10 and -35 elements were converted into their respective consensus sequences. The mutant promoters thus obtained were tested for their activities in both the E. coli and B. subtilis host cells. The change of the length of the spacer region from 12 to 17 bp resulted in a 1.6- and 2.5-fold increase in promoter strength in comparison with the wild type promoter in E. coli and B. subtilis cells, respectively. Also, strength of the promoter with the fourth T to A transversion on its -35 element increased in the transcription level by about 35 times compared with that of wild-type promoter. However, surprisingly the 5' end C-to-T transition of the -10 hexamer showed a 5- to 15-fold reduction in $\beta$-xylosidase activity in both E. coli and B. subtilis. Together, the present data demonstrated that the 5' end nucleotide C of the -10 sequence CATAAT and the fourth nucleotide A of the -35 hexamer are two most critical nucleotides for the promoter activity in the context of the xylA promoter.

• The Korean Journal of Food And Nutrition
• /
• v.15 no.2
• /
• pp.104-111
• /
• 2002

The peptidyl prolyl sis-trans isomerase (PPIase, EC 5.2.1.8) from bacillus stearothermophilus was extracted from the cells treated with by lysozyme. PPIase was purified from the cell extracts by heat treatment, ammonium sulfate precipitation, ion exchange chromatography and finally gel filtration, sodium dodecyl sulfate polyacrylamide gel electrophoresis(SDS-PAGE). The molecular weight of the purified PPIase was estimated as 18kDa by SDS-PAGE. The 39 amino acid residues from the N-terminus were determined by the protein sequencer. The enzyme showed the optimum pH at 8.0 and was stable at the range of pH 7.0∼8.0. The enzyme was considerably stable after heat treatment at 60$\^{C}$ for 30minutes, and the enzyme was quite stable up to 65$\^{C}$. The presence of the PPIase in the refolding solution accelerated the isomerization rate of the assay peptide. PPIase gene of Bacillus stearothermophilus was screened from a genomic library by plaque hybridization using the A-l primer as a probe. A PPIase positive plaque contained a 3.0kb insert of the chromosomal DNA. A 3.0kb fragment was subcloned into pUC18, resulting pPI-40. A DNA fragment encoding the N-terminal portion of the PPIase in pPI-40 was amplified by polymerase chain reaction(PCR) method using the A-1 and B-2 primers. The amplified fragment was cloned into the Sma I site of pUC18 and recombinant plasmid was designated as pSN-18. The nucleotide sequence of 167bp fragment was determined. The deduced amino acid sequence of PPIase was completely matched with the determined N-terminal amino acid sequence of PPIase B. stearothermophilus.

• Journal of Food Hygiene and Safety
• /
• v.21 no.3
• /
• pp.159-163
• /
• 2006

37 Bacillus spp strains(43.0%=37/86), and 18 B. cereus(20.9%=18/86) were isolated on 86 dried marine products. Each isolates were B. cereus 48.6%(18/37), B. mycoides 13.5%(5/37) B. coagulus 5.4%(2/37) B. firmus 5.4%(2/37), B. circulus 2.7%(1/37), B. stearothermophilus 2.7%(1/37), B. pumilus 2.7%(1/37) B. spp. 8.1%(3/37), and Brebacillus brevis 10.8%(4/37) etc.

• Microbiology and Biotechnology Letters
• /
• v.22 no.6
• /
• pp.607-613
• /
• 1994

The Bacillus stearothermophilus arfI gene encoding a-arabinofuranosidase was isolated from the genomic library, cloned into pBR322, and subsequently transferred into the Escherichia coli HB101. The recombinant E. coli was selected from approximately 10,000 transformants screened by making use of its ability to produce a yellow pigment around the colony on the selective medium supplemented with p-nitrophenyl-$\alpha$-L-arabinofuranoside (pNPAf), a chromogenic substrate. The functional clone was found to harbor a recombinant plasmid, pKMG11 with an insertion of about 5 kb derived from the B. stearothermophilus chromosomal DNA. Identity of the arfI gene on the insert DNA was confirmed by a zymogram with 4-methylumbelliferyl-$\alpha$-L-arabinofuranoside as the enzyme substrate. The $\alpha$-arabinofuranosidase from the recombinant E. coli strain showed very high substrate specificity; the enzyme displayed high activity only with pNPAf among many other p- or $o$-nitrophenyl derivatives of several sugars, and acted only on arabinoxylan among various natural arabinose containing polysaccharides tested.

• Food Science and Biotechnology
• /
• v.14 no.1
• /
• pp.46-48
• /
• 2005

Growth inhibitory effects of ethanol extracts of green tea and pine needles on Bacillus stearothermophilus isolated from spoiled red bean paste were detected at concentrations higher than 750 ppm, and antimicrobial activity of pine needle extract was slightly higher than that of green tea exract. Growth inhibitory effect of pine needle extract in nutrient broth adjusted to pH 6.0, water-activity 0.92, and $45\;^{\circ}$Brix was observed at 500 ppm. These results indicated growth of B. stearothermophilus could be inhibited by adding pine needle and green tea extracts.

• Journal of Microbiology and Biotechnology
• /
• v.8 no.1
• /
• pp.14-20
• /
• 1998

Syntheses of the B. stearothermophilus xylanolytic enzymes such as xylanases, ${\beta}$-xylosidases, ${\alpha}$-arabinofurano-sidases, and esterases, were observed to be regulated by the carbon source present in the culture media. Xylan induced synthesis of ${\beta}$-xylosidase at the highest level while xylose gave about 30% of the ${\beta}$-xylosidase activity induced by xylan. The lowest syntheses of the xylanolytic enzymes above mentioned were detected in the basal medium containing glucose as a sole carbon source. When a mixture of xylan and glucose was used as a carbon source, we could observe glucose repression of xylanase (about 70-fold) and ${\beta}$-xylosidase (about 40-fold) syntheses. Whereas, the level of the glucose repression of the expression of the xylA gene encoding the major ${\beta}$-xylosidase of B. stearothermophilus was assessed to be about l0-fold when the relative amounts of the xylA transcript were determined. From the sequence of the xylA gene, we could find two CRE-like sequences (CRE-l: nucleotides ＋124 to ＋136 and CRE-2:＋247 to ＋259) within the reading frame of the xylA gene, either or both of which were suspected to be involved in catabolite repression of the xylA gene.

• Microbiology and Biotechnology Letters
• /
• v.23 no.4
• /
• pp.446-453
• /
• 1995

$\alpha $-Arabinofuranosidase was produced by E. coli HB101 haboring the recombinant plasmid pKMG11 which contained the arfI gene of Bacillus stearothermophilus. The maximum production of the enzyme was observed when E. coli HB101 cells were grown at 37$\circ$C for 20 hours in the medium containing 0.5% arabinose, 1.0% tryptone, 0.5% yeast extract, and 1% NaCl. The $\ALPHA $-arabinofuranosidase produced was purified to homogeneity using a combination of 20-50% ammonium sulfate precipitation, DEAE-Sepharose CL-6B ion exchange column chromatography and Sepharose 6B-100 gel filtration. The purified enzyme was most active at 55$\circ$C and pH 6.5. The K$_{m}$ and V$_{max}$ values of the enzyme on $\rho $-nitrophenyl-$\alpha $-arabinofuranoside was determined to be 2.99 mM and 0.43 $\mu $mole/min (319.74 $\mu $mole/min/mg), respectively. The pI value was 4.5. The molecular weight of the native protein was estimated to be 289 kDa. The SDS-polyacrylamide gel clectrophoresis analysis suggested that the functional protein was a trimer of the 108 kDa identical subunits. The N-terminal amino acid sequence of the a-arabinofuranosidase was identified as X-Ser-Thr-Ala-Pro-Arg( \ulcorner )-Ala-Thr-Met-Val-Ile-Asp-X-Ala-Phe.